Pressure regulating device



June 12, 1956 LONG 2,749,925

PRESSURE REGULATING DEVICE Filed Nov. 29, 1951 22 m y I i 20 INVENTOR.

L. L. LONG A 7' TORNEK?- United States Patent "Ofice 2,749,925 PatentedJune 12, 1956 PRESSURE REGULATING DEVICE Loren L. Long, Alvin, Tex.,assignor to Phillips Petroleum Company, a corporation of DelawareApplication November 29, 1951, Serial No. 258,846

7 Claims. (Cl. 137-1) This invention relates to pressure regulatingdevices. In one of its aspects this invention relates to a pressureregulating device in combination with a vortex tube. In still another ofits aspects this invention relates to a method and apparatus for theprevention of plugging or freezing of a pressure regulating device.

When a pressure regulating device is employed to ,pass a gas at arelatively high pressure to a relatively low pressure difficulties areoften encountered in the operation of these valves due to the formationof ice or solid materials such asgas hydrates. Ice and/or gas hydratesare-often formed in natural gas lines due to the reduced temperature ofthe gas after having passed through a pressure regulating device from ahigh pressure zone to a low pressure zone. In natural gas collecting anddistributing systems freezing and plugging of back pressure regulatingdevices and pressure relief valves are often encountered due to theformation of ice and'solid gas hydrates on the outlet side of thesedevices. In the handling of natural gas at high pressures and with watervapor therein gas hydrates are easily formed. Gas hydrates areessentially a solid molecular complex of a paraflinic hydrocarbon suchas methane, ethane, propane, butane, isobutane, etc. and water, atypical gas hydrate can be represented by CH4.7H2O. Depending upon thepressure and temperaturethese hydrocarbons form solid hydrates withwater vapor. Solid gas hydrate forming conditions are found within thetemperature range 3090 F. and form about 10 to 10,000 p. s. i.g.; ingeneral the higher the temperature the higher the pressure necessary toform solid gas hydrates.

'In natural gas collecting and distributing systems pressure surges areoftentimes experienced. These pressure surges may reach dangerously highvalues. In order to prevent pressure in natural gas systems fromreaching dangerously high levels, pressure release valves areincorporated therein. These pressure release-valves are set or adjustedto release a high pressure gas at certain predetermined values. Inoperation however, difiiculty is encountered due to the formation ofsolid gas hydrates or ice on the outlets of such valves. In actualpractice it has beenfoun'd that when a pressure relief valve opens topass gas therethrough in order to reduce the pressure in that particularpart of the system, solid gas hydrate formation sometimes occurs due tothe rapidand sudden expansion of the gases. The solid gas hydrate oftenplugs the outlet side of the pressure relief valve and effectively shutsoff the flow of -high pressure gas therethrough.

When this condition occurs there is great danger of failure of some partof the system due to the high pressure. Another difiiculty encounteredin the operation of these valves is the formation of ice therein due tothe rapid cooling of the gas as it expands through the pressure releasevalve.

Accordingly, it is an object of this inventiontoprovide an improvedpressure regulating device. It is another object of this invention toprovide a means and method for the prevention of solid gas hydrateformation within a mosphere.

pressure regulating device. It is still another object of this inventionto provide a means and method of maintaining pressure regulating devicesat an elevated temperature to prevent plugging by ice or gas hydrates.Other objects, features and advantages will be apparent and suggestthemselves to those skilled in the art from the accompanying drawingsand disclosure. In at least one aspect of this invention, at least oneof these objects will be achieved.

In accordance with my invention I have provided an apparatus and methodfor preventing the formation of solid gas hydrates and ice within apressure regulating device. My invention comprises a pressure regulatingdevice in combination with a vortex tube. In accordance with oneembodiment of my invention highpressuregases upon passing through apressure regulating device enter a vortex tube. The gaseous effluentfrom the hotend of the vortex tube is then passed in heat exchangerelation- .ship with the pressure regulating device. These hot gasesfrom the vortextube are employedto heat and increase the temperature ofthe pressure regulating device so as to .prevent formation of solid iceor solid gas hydrates therein.

The vortex tube is a device which is well known and comprisesessentially a tube wherein a gas is admitted tangentially. Due to theconfiguration of inner surfaces of the vortex tube the gas is separatedinto two streams, a relatively high pressure, high temperature streamand a relatively low pressure, low temperature stream. These streams maybe separately recovered from the vortex tube. Depending upon thetemperature and pressure ,of the entering gases to the vortex tube anddepending upon theparticular design of the vortex tube, the temperaturedifferential between the hot stream and the coolstream issuing from thevortex tube may range between 50250 F. Higher orlower temperaturedifferentials of course may be obtained depending upon the particulardesign of the vortex tube. Fora more complete-understanding of thevortex tube, how it is constructed and for a description of how a highand a low temperature stream is produced, reference is made to'U. S.Patent 1,952,281. The disclosures of this patent relative to theconstruction and operation of a vortex tube are herein incorporated andmade a part of this disclosure.

The invention will be better understood and the method and apparatus ofthis invention will become more apparent from the following discussionmade with reference to the accompanying drawings Figs. 1, 2, and 3wherein Fig. l is across-sectional side view of one embodiment of thisinvention showing a vortex tube in combination with a pressure reliefvalve and wherein Fig. 2 is a cross-sectional plan view of the samedevice illustrated by Fig. 1 and wherein Fig. 3 is a cross-sectionalplanview of a typical vortex tube.

Referring now to Fig. 1, a jacketltl is shown enclosing valve body'll. Aconduit 12 is shown connectedto valve body '11 and'communicating with asuitable source of high pressure gas, such as container 13. The outletend of conduit 12 within valve body 11 is closed by a suitable valve,plug 15 which is positioned thereover;by pressure responsive meansjld,such as a spring, so as to maintain plug 1'5 in position to seal off theoutlet end of;conduit 12 within valve body '11. Con'duit 18 communicatesthe interior of valve body '11 with vortex-tube:19. Vortex tube 19 hastwo outlets, a low temperature outlet 720 and a high temperature outlet21, and an inlet 26. 'The low temperature outlet may be connectedby,conduit 22 torany suitable system or may lead directly to the at-Conduit 23 connects the high temperature outletof vortex tube19 withjacket 10. Jacket10 is provided with an outlet 25.

Referring now to Fig. 2 there is shown a cross-sectional plan view ofthe apparatus illustrated by Fig. 1. Those clarity in order to betterunderstand how a vortex tube is incorproated in a pressure regulatingdevice in accordance with this invention.

Referring now to Fig. 3 therein is shown a crosssectional plan view ofthe vortex tube employed in the apparatus of Fig. 1. Fig. 3 shows inlet26 to the vortex tube and the inner surface 27 of the vortex tube.

The operation of the apparatus of the invention is simple. Wheneverpressure responsive means 16 is caused to move upward or is compresseddue to the pressure of the gas in conduit 12, valve plug 15 is moved offthe outlet end of conduit 12. As a result gas will flow through conduit12 into valve body 11 through conduit 18 into vortex tube 19. Since alower pressure exists at each of the outlets of the vortex tube than atthe inlet to the tube, the entering gas will flow out of both of theoutlets. Substantially all of the gas flowing out of low temperatureoutlet 20 comes from the center of the tube while substantially all ofthe gas flowing out of high temperature outlet 21 is collected from theperiphery of the tube. This latter gas is at a substantially highertemperature than the gas removed from the center of the tube. Whether anoutlet serves as a high or low temperature outlet depends entirely uponthe construction of the vortex tube. By merely altering the constructionof the tube so that the direction of flow of the hot and cold gases isreversed, an outlet can be changed from a high to a low temperatureoutlet or vice versa. The low temperature, cold stream from outlet 20 ofthe vortex tube enters conduit 22 and is suitably recovered or utilized.The high temperature, hot stream from outlet 21 of the vortex tube ispassed via conduit 23 into jacket wherein it is passed in heat exchangerelationship with valve body 11. The hot gaseous stream leaving jacket10 via conduit 25 may be suitably recovered or utilized.

According to one embodiment of this invention as illustrated withrespect to Figs. 1 and 2, the vortex tube is employed in essentially onedevice and in combination with a pressure release valve. According toanother embodiment of this invention the pressure release valve may becontained within a structure separate from that which contains thevortex tube and a conduit could connect the hot end of the vortex tubewith a suitable heat exchange meansjor the pressure release valve.

This invention is of course not limited in use to an apparatus whichoperates intermittently. This invention 7 sure reducing or regulatingdevice.

Many obvious changes in construction and design and other applicationswill be apparent and suggest themselves to those skilled in the art uponreading this disclosure without departing from the spirit or scope ofthis invention.

I claim:

1. A method for heating a pressure regulating device wherein a gas at ahigh pressure is passed therethrough to a lower pressure which comprisespassing at least a portion of the high pressure gas passing through saidpressure regulating device into a separation zone; separating in saidzone said portion of high pressure gas into a high temperature gasstream and a low temperature gas stream; and passing said hightemperature gas stream in heat exchange relationship with said pressureregulating device.

2. A method for preventing plugging of a pressure relief valve due tothe formation of gas hydrates which com-- prises passing at least aportion of the gas released by said pressure relief valve into aseparation zone; separatingin said zone said portion of the gas releasedby said pressure relief valve into a high temperature gas stream and alow temperature gas stream; and passing said high temperature gas streamin heat exchange relationship with said valve.

3. A pressure regulating device comprising in combination a valve body;a jacket in heat exchange relationship and in contact with at least aportion of said valve body; an inlet for said valve body and incommunication with a source of gas at high pressure; a closure sealingofl said inlet; a chamber above said closure; pressure responsive meanswithin said chamber positioned to maintain said closure in position toseal ofi said inlet; a vortex tube having an inlet, a low temperatureoutlet and a high temperature outlet; a first conduit connecting saidinlet of said vortex tube with said chamber; and a second conduitconnecting the high temperature outlet of said vortex tube with saidjacket.

4. A pressure regulating device comprising in combination a valve body;a heat exchange jacket surrounding said valve body; an inlet for saidvalve body; a chamber within said valve body with which said inletcommunicates; a plug within said chamber positioned over said inlet;pressure responsive means Within said chamber and tending to keep saidplug in position over said inlet; a vortex tube having an inlet, a lowtemperature outlet and a high temperature outlet; a first conduitconnecting the inlet of said tube with said chamber; and a secondconduit connecting the high temperature outlet of said tube with saidjacket.

5. A pressure regulating device comprising in combination a valve body;a heat exchange jacket surrounding said valve body; a chamber withinsaid valve body; an inlet to said chamber, a closure Within said chamberpositioned over said inlet; a spring within said chamber bearing on oneend against that portion of said chamber opposite said inlet and at theother end tending to keep said closure in position over said inlet; avortex tube having an inlet, a low temperature outlet and a hightemperature outlet; a first conduit connecting the inlet of said tubewith said chamber; and a second conduit connecting the high temperatureoutlet of said tube with said jacket.

6. A pressure release apparatus comprising a pressure relief valve; ajacket surrounding said valve; a vortex tube in combination with saidvalve, said tube having an inlet, a low temperature outlet and a hightemperature outlet; a first conduit connecting the inlet of said vortextube with the interior of said valve; and a second conduit connectingthe high temperature outlet of said vortex tube with said jacket.

7. An apparatus comprising a pressure regulating valve; a jacket in heatexchange relationship with at least a portion of said valve; a vortextube in combination with said valve, said vortex tube having an inlet, alow temperature outlet and a high temperature outlet; a valve outletconduit extending between said valve and the inlet of said vortex tube;and a conduit communicating the high temperature outlet of said vortextube with said jacket.

References Cited in the file of this patent UNITED STATES PATENTS1,321,343 Vuilleumier Nov. 11, 1919 1,952,281 Ranque Mar. 27, 19341,988,769 Aldridge et al. Jan. 22, 1935 2,520,302 Barnes Aug. 29, 19502,638,917 Clair May 19, 1953 FOREIGN PATENTS 166,542 Great Britain Jan.5, 1922

1. A METHOD FOR HEATING A PRESSURE REGULATING DEVICE WHEREIN A GAS AT AHIGH PRESSURE IS PASSED THERETHROUGH TO A LOWER PRESSURE WHICH COMPRISESPASSING AT LEAST A PORTION OF THE HIGH PRESSURE GAS PASSING THROUGH SAIDPRESSURE REGULATING DEVICE INTO A SEPARATION ZONE; SEPARATING IN SAIDZONE SAID PORTION OF HIGH PRESSURE GAS INTO A HIGH TEMPERATURE GASSTREAM AND A LOW TEMPERATURE GAS STREAM; AND PASSING SAID HIGHTEMPERATURE GAS STREAM IN HEAT EXCHANGE RELATIONSHIP WITH SAID PRESSUREREGULATING DEVICE.